1. Field of the Invention
The present invention relates to an apparatus for efficiently extracting potable water from the ocean.
2. Description of the Prior Art
With the continuing expansion of world population, the need for new sources of potable water has been long recognized. These needs have led to the development of numerous different prior art devices for extracting fresh water from the ocean. Other efforts have explored various mechanisms for converting the hydrokinetic energy of waves into useable energy. These devices may be broken into two general categories. One category relates to various piston type pumps carried from articulated framework including a float fluctuated by waves. The system is then typically moored from the ocean floor in hopes that the undulating ocean surface will induce sufficient consistent relative movement between the piston pump and the cylinder housing to thereby reciprocate the piston to pump fluid therefrom to generate a pressure from which energy may be extracted. Devices of this general description are shown in U.S. Pat. No. 3,487,228 to Kriegel, U.S. Pat. No. 4,260,901 to Woodbridge, U.S. Pat. No. 4,421,461 to Hicks and U.S. Pat. No. 4,335,576 to Hopfe. Such devices, while being acceptable for their intended purpose, suffer the shortcoming that they do not reliably produce sufficient energy for operation of a reverse osmosis type desalination device.
Other wave powered generators have been proposed which are anchored to the ocean floor and incorporate a piston style pump driven by a float contained within a resonant chamber exposed to incoming waves and configured to amplify such waves. A device of this type is shown in U.S. Pat. No. 4,594,853 to Raichlen et al. and assigned to the assignee of this application. Such devices have proven efficient to generate power but, heretofore, have not been employed in combination with a desalination device for separating fresh water from brine.
Efforts to harness the ocean waves for the purpose of distilling fresh water from the ocean have led to proposals that movement of the waves be harnessed to generate a partial vacuum to thereby vaporize fresh water from the ocean water. A device of this type is shown in U.S. Pat. No. 4,120,756 to Carman. While such devices are satisfactory for their intended purpose, they suffer the shortcoming that the unamplified waves have proven inefficient for continuously and repeatedly generating a high partial vacuum for efficient production of a practical volume of vapor.
Efforts to devise an efficient wave powered desalination system have led to the proposal of a piston pump the water through a heat exchanger, evaporator and condenser. The piston was driven in a conventional articulated cylindrical housing and piston arrangement coupled with a float. A device of this type is shown in U.S. Pat. No. 4,555,307 to Hagen. While acceptable for its intended use, such a device fails to provide the desired low cost, reliable and highly efficient desalination mechanism having ready practical application.
Consequently, there exists a need for a desalination apparatus which is sturdy in construction, resistant to the elements and which is dependent only on the undulating ocean water for its power source.